Purchase river rocks labeled for aquarium use. Craft-store rocks can be coated in chemicals.

And with a balance in mind, there’s a greater habitat issue to consider… when I do finally choose the substrate best suited to my tank, I do my best to purchase materials packaged in recyclable containers. That can be especially difficult when it comes to the river rocks.

I simply will not buy those packaged in plastic netting. Nasty stuff and exceptionally hazardous to wildlife when it winds up in landfills or the world’s oceans. Instead, I support places that sell rocks and slabs in bulk bins.